Some examples of known injection molding systems are: (i) the HyPET™ Molding System, (ii) the Quadloc™ Molding System, (iii) the Hylectric™ Molding System, and (iv) the HyMet™ Molding System, all manufactured by Husky Injection Molding Systems, Ltd. of Bolton, Ontario, Canada. These injection molding systems include components that are known to persons skilled in the art and these known components will not be described here; these known components are described, by way of example, in the following references: (i) Injection Molding Handbook by Osswald/Turng/Gramann ISBN: 3-446-21669-2; publisher: Hanser, and (ii) Injection Molding Handbook by Rosato and Rosato ISBN: 0-412-99381-3; publisher: Chapman & Hill. Injection molding systems typically include an injection actuator to motive a reciprocating screw or plunger.
US patent application 2003/0185932A1 (published 2003-10-02) to CHROMY et al, teaches an injection screw drive for a plastic injection molding machine comprising axes (A1, A2) respectively provided for the rotational and for the axial motion of the injection screw (4). According to the invention, the injection screw drive has at least one double rack rail overdrive for effecting the axial motion. The injection worm drive is configured as a gear combination having at least two drive motors (18, 44) and an output axle. The gear combination has, as a core, a gear block with a gear casing (42), to which at least two reducing gears are connected that effect the rotational and the axial motion of the injection screw (4). This enables the entire machine to be provided with a short and compact structure insofar as this concerns the injection aggregate. According to a second embodiment, both drives have separate housings. The entire injection unit rests, in a known manner, on the machine stand (33) via guide rails (32) such that it can be displaced.
U.S. Pat. No. 7,004,742 to Ickinger (issued 2006-02-28) teaches a linear drive for an injection molding machine including a housing defining a sealed interior space containing a gas volume. The housing has two housing portions constructed for telescopic movement within one another. A spindle drive is accommodated in the housing and operated by the electric motor. The spindle drive includes a spindle shaft, which is axially securely fixed to one of the housing portions, and a spindle nut, which is arranged on the spindle shaft and axially securely fixed to the other one of the housing portions. Acting on the spindle drive is an energy accumulator which is constructed for discharge in a first operating cycle which is energy-intensive and for recharging in a second operating cycle which is opposite to the first operating cycle and requires little energy.